Parkinson’s disease (PD) is a chronic and progressive movement disorder affecting almost one million people in the United States. About 60,000 Americans get a Parkinson’s diagnosis every year.
This condition develops when the brain doesn’t produce enough dopamine, the “pleasure” neurotransmitter which also helps control movements and coordination.
Experts predict its growth to continue and extend to younger people. Such a somber reality makes early detection increasingly urgent.
However, this has been difficult since PD shares symptoms with other neurological disorders.
Researchers at the University of Manchester in the United Kingdom say that they have found a way to check skin secretions for PD. Their simple, three-minute process uses cotton swabs and mass spectrometryTrusted Source to detect hundreds of unique lipids associated with the disease.
They believe that the “identification of robust biomarkers to complement clinical diagnosis will accelerate treatment options.”
Challenges diagnosing Parkinson’s
Presently, no definitive test exists for Parkinson’s disease. Healthcare specialists assess symptoms, medical history, and brain scans to reach a diagnosis.
Mark Frasier, Ph.D. is the Chief Scientific Officer of the Michael J. Fox Foundation for Parkinson’s Research. In a podcast from April 2022, Dr. Frasier explained the diagnosing dilemma:
“[It] can be a really long journey […] to get a diagnosis, because Parkinson’s can look like a lot of different things. And aging introduces many different complicated factors that may not be Parkinson’s. The way it is currently done and is typically in a [neurologist’s] office, they will perform tapping tests and have individuals walk and assess their movements.”
“It’s really up to the neurologist to make that diagnosis. And it’s hard because symptoms wax and wane from day to day and even from hour to hour. It’s often hard for a neurologist to really assess those symptoms in a 20-minute visit,” he explained.
Parkinson’s distinct odor and Joy Milne
Increased production of sebum, an oily substance naturally present on all human skin, is a telltale symptom of Parkinson’s disease, first documented in 1927.
Biofluid analysesTrusted Source have revealed that the onset of PD can produce changes in its composition.
The present study was inspired by Joy MilneTrusted Source, a Scottish woman and retired nurse with hereditary hyperosmia — unusual, heightened sensitivity to smells. Previous researchTrusted Source reported that Milne noticed one day that her husband’s characteristic scent had changed before he showed any clinical symptoms of Parkinson’s.
Milne’s husband, Les, was eventually diagnosed with the disease more than a decade after Milne first detected the odor. After the formal diagnosis, the couple met others in a Parkinson’s UK support group, and Milne immediately noticed they had the same distinctive smell. It wasn’t until then that she linked the odor to PD. Les died in 2015.
Milne had since partnered with scientists to further study her “super smeller” capabilities and how this may help improve the diagnosis and treatment of the disease.
Prof. Perdita Barran, Ph.D., who led the present study at the University of Manchester, told the BBC that the potential of a diagnostic test for Parkinson’s disease would be “transformative” since there is currently no chemical test available. In the interview with the BBC, Prof. Barran said the researchers are looking to collaborate with local hospital labs and implement the test within the Manchester area in the next two years.
Analyzing sebum to detect Parkinson’s
The Manchester team recruited people from 27 clinics throughout the UK, collecting 150 sebum samples from participants, including 79 samples from people with PD. The remaining 71 were used as controls from individuals without the disease.
The researchers rubbed the mid-back of subjects with medical cotton swabs to collect the skin’s oils. Then, they transported the samples to a facility until testing.
Next, chemists transferred the sebum onto filter paper, which they cut into small triangles.
Adding solvent and applying voltage helped transfer the sebum’s constituents into a mass spectrometer.
The co-authors said: “Here, we demonstrate the use of direct infusion of sebum from skin swabs using paper spray ionization coupled with ion mobility mass spectrometry […] to determine the regulation of molecular classes of lipids in sebum that are diagnostic of PD.”
Ultimately, 4,200 unique features were detected. Of these, 500 were different between individuals with PD compared to the control group.
Neurologist Prof. Monty Silverdale, Ph.D., the study’s clinical lead, noted: “This test has the potential to massively improve the diagnosis and management of people with Parkinson’s disease.”
Medical News Today discussed this research with Dr. Natalie Diaz, a neurologist at the Pacific Movements Disorder Center at Pacific Neuroscience Institute in Santa Monica, CA. She was not involved in the study.
Dr. Diaz noted that the Manchester researchers’ findings might suggest that their method can identify PD patients. However, she said: “Unlike previous studies from this group, there is no clinical data available on the PD patients enrolled into this study to understand if this rapid and inexpensive method is sensitive enough to identify PD patients in the early, untreated stage versus those without PD.”
She also mentioned: “As no information is given as to how the diagnosis of PD was made, it is also unclear if sebum as a biomarker would help differentiate patients with early PD versus other forms of degenerative parkinsonism.”
Dr. Diaz was impressed that testing sebum can be noninvasive and may be cost-effective. She wondered, though, how its sensitivity and accuracy compare to current diagnostic tools.
Some individuals may produce less or more sebum, affecting testing results.
Seborrhea Trusted Sourceor seborrheic dermatitis affects about 5% of adults. This skin condition, commonly associated with PD, might lower sebum production.
The study’s authors acknowledged that sample collection efficiency could differ from person to person.